Hi Martin,
> The changes I made in the Xorg evdev driver mainly follow along the line that > Stephane and his team already did (I even copied parts of their code). > Because I had a special target device in mind that also runs "legacy" X > applications (i.e. w/o multitouch support of any kind), I also cared about > not breaking things with these apps, ending up in only sending button events > for the primary finger on the screen as well as always sending the > coordinates of the primary finger in the "non-MT" Abs fields. This is actually standard procedure in the kernel, although there were problems initially with the 72a1 device. > I also added a little convenience in the kernel's input.h which basically is > a > bitfield that keeps track of the fingers on the screen by setting the bits of > the corresponding tracking IDs to 1 during touchdown. This is exported as > just another button in the event device. As I avoided button events for all > non-primary fingers, this bitfield makes it easy to keep track > of "non-primary" touches and releases and also comes in handy when doing > event compression (see the Qt patches for that). I see. Nowadays, with mtdev and full kernel support for the 72a1, you should be able to do well without the bitfield, I take it? > It turns out that > multitouch-aware Qt applications work like a charm and even the legacy > applications do (no jumping or locking "mouse-pointer" when (accidentally) > hitting the screen with the second finger). > > Another useful thing when using the actual Xorg driver to relay the > multitouch > events (instead of directly working on /dev/input/eventXX from within the > application layer) is the fact that software can very easily be tested on the > actual multitouch device (in our case a slate) without even compiling on the > device, just forward the X screen to the target device. With that you can do > funny things like running the test application on your (fast-compiling) > 64-bit workstation while having the output and the input on your 32-bit > slate. > > Anyway, here is a URL to the patches as well as a small description: > http://www.digitalmedics.de/projects/wetab > Note that these patches currently only work for a certain (hid-egalax.c) > device, as they were targeted at a special hardware platform. However, the > code is written in a quite general way, so that adaptions to other hardware > should be easy, in fact it suffices to work on the kernel HID layer. > As the manufacturer of the slate device is already in the process of > incorporating these patches into their system, I will take down the page in a > couple of weeks. I felt that before I take it down, maybe those patches are > of use to someone else, if not I apologize for wasting your time :) Thanks for sharing! Henrik _______________________________________________ Mailing list: https://launchpad.net/~multi-touch-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~multi-touch-dev More help : https://help.launchpad.net/ListHelp
